2 * Copyright (c) 2017 Linaro Ltd.
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 and
6 * only version 2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
14 #include <linux/kernel.h>
15 #include <linux/cdev.h>
16 #include <linux/err.h>
17 #include <linux/module.h>
18 #include <linux/platform_device.h>
20 #include <linux/of_reserved_mem.h>
21 #include <linux/dma-mapping.h>
22 #include <linux/slab.h>
23 #include <linux/uaccess.h>
25 #include <linux/qcom_scm.h>
27 #define QCOM_RMTFS_MEM_DEV_MAX (MINORMASK + 1)
29 static dev_t qcom_rmtfs_mem_major;
31 struct qcom_rmtfs_mem {
39 unsigned int client_id;
44 static ssize_t qcom_rmtfs_mem_show(struct device *dev,
45 struct device_attribute *attr,
48 static DEVICE_ATTR(phys_addr, 0444, qcom_rmtfs_mem_show, NULL);
49 static DEVICE_ATTR(size, 0444, qcom_rmtfs_mem_show, NULL);
50 static DEVICE_ATTR(client_id, 0444, qcom_rmtfs_mem_show, NULL);
52 static ssize_t qcom_rmtfs_mem_show(struct device *dev,
53 struct device_attribute *attr,
56 struct qcom_rmtfs_mem *rmtfs_mem = container_of(dev,
57 struct qcom_rmtfs_mem,
60 if (attr == &dev_attr_phys_addr)
61 return sprintf(buf, "%pa\n", &rmtfs_mem->addr);
62 if (attr == &dev_attr_size)
63 return sprintf(buf, "%pa\n", &rmtfs_mem->size);
64 if (attr == &dev_attr_client_id)
65 return sprintf(buf, "%d\n", rmtfs_mem->client_id);
70 static struct attribute *qcom_rmtfs_mem_attrs[] = {
71 &dev_attr_phys_addr.attr,
73 &dev_attr_client_id.attr,
76 ATTRIBUTE_GROUPS(qcom_rmtfs_mem);
78 static int qcom_rmtfs_mem_open(struct inode *inode, struct file *filp)
80 struct qcom_rmtfs_mem *rmtfs_mem = container_of(inode->i_cdev,
81 struct qcom_rmtfs_mem,
84 get_device(&rmtfs_mem->dev);
85 filp->private_data = rmtfs_mem;
89 static ssize_t qcom_rmtfs_mem_read(struct file *filp,
90 char __user *buf, size_t count, loff_t *f_pos)
92 struct qcom_rmtfs_mem *rmtfs_mem = filp->private_data;
94 if (*f_pos >= rmtfs_mem->size)
97 if (*f_pos + count >= rmtfs_mem->size)
98 count = rmtfs_mem->size - *f_pos;
100 if (copy_to_user(buf, rmtfs_mem->base + *f_pos, count))
107 static ssize_t qcom_rmtfs_mem_write(struct file *filp,
108 const char __user *buf, size_t count,
111 struct qcom_rmtfs_mem *rmtfs_mem = filp->private_data;
113 if (*f_pos >= rmtfs_mem->size)
116 if (*f_pos + count >= rmtfs_mem->size)
117 count = rmtfs_mem->size - *f_pos;
119 if (copy_from_user(rmtfs_mem->base + *f_pos, buf, count))
126 static int qcom_rmtfs_mem_release(struct inode *inode, struct file *filp)
128 struct qcom_rmtfs_mem *rmtfs_mem = filp->private_data;
130 put_device(&rmtfs_mem->dev);
135 static struct class rmtfs_class = {
136 .owner = THIS_MODULE,
140 static int qcom_rmtfs_mem_mmap(struct file *filep, struct vm_area_struct *vma)
142 struct qcom_rmtfs_mem *rmtfs_mem = filep->private_data;
144 if (vma->vm_end - vma->vm_start > rmtfs_mem->size) {
145 dev_dbg(&rmtfs_mem->dev,
146 "vm_end[%lu] - vm_start[%lu] [%lu] > mem->size[%pa]\n",
147 vma->vm_end, vma->vm_start,
148 (vma->vm_end - vma->vm_start), &rmtfs_mem->size);
152 vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
153 return remap_pfn_range(vma,
155 rmtfs_mem->addr >> PAGE_SHIFT,
156 vma->vm_end - vma->vm_start,
160 static const struct file_operations qcom_rmtfs_mem_fops = {
161 .owner = THIS_MODULE,
162 .open = qcom_rmtfs_mem_open,
163 .read = qcom_rmtfs_mem_read,
164 .write = qcom_rmtfs_mem_write,
165 .release = qcom_rmtfs_mem_release,
166 .llseek = default_llseek,
167 .mmap = qcom_rmtfs_mem_mmap,
170 static void qcom_rmtfs_mem_release_device(struct device *dev)
172 struct qcom_rmtfs_mem *rmtfs_mem = container_of(dev,
173 struct qcom_rmtfs_mem,
179 static int qcom_rmtfs_mem_probe(struct platform_device *pdev)
181 struct device_node *node = pdev->dev.of_node;
182 struct qcom_scm_vmperm perms[2];
183 struct reserved_mem *rmem;
184 struct qcom_rmtfs_mem *rmtfs_mem;
189 rmem = of_reserved_mem_lookup(node);
191 dev_err(&pdev->dev, "failed to acquire memory region\n");
195 ret = of_property_read_u32(node, "qcom,client-id", &client_id);
197 dev_err(&pdev->dev, "failed to parse \"qcom,client-id\"\n");
202 rmtfs_mem = kzalloc(sizeof(*rmtfs_mem), GFP_KERNEL);
206 rmtfs_mem->addr = rmem->base;
207 rmtfs_mem->client_id = client_id;
208 rmtfs_mem->size = rmem->size;
210 device_initialize(&rmtfs_mem->dev);
211 rmtfs_mem->dev.parent = &pdev->dev;
212 rmtfs_mem->dev.groups = qcom_rmtfs_mem_groups;
213 rmtfs_mem->dev.release = qcom_rmtfs_mem_release_device;
215 rmtfs_mem->base = devm_memremap(&rmtfs_mem->dev, rmtfs_mem->addr,
216 rmtfs_mem->size, MEMREMAP_WC);
217 if (IS_ERR(rmtfs_mem->base)) {
218 dev_err(&pdev->dev, "failed to remap rmtfs_mem region\n");
219 ret = PTR_ERR(rmtfs_mem->base);
223 cdev_init(&rmtfs_mem->cdev, &qcom_rmtfs_mem_fops);
224 rmtfs_mem->cdev.owner = THIS_MODULE;
226 dev_set_name(&rmtfs_mem->dev, "qcom_rmtfs_mem%d", client_id);
227 rmtfs_mem->dev.id = client_id;
228 rmtfs_mem->dev.class = &rmtfs_class;
229 rmtfs_mem->dev.devt = MKDEV(MAJOR(qcom_rmtfs_mem_major), client_id);
231 ret = cdev_device_add(&rmtfs_mem->cdev, &rmtfs_mem->dev);
233 dev_err(&pdev->dev, "failed to add cdev: %d\n", ret);
237 ret = of_property_read_u32(node, "qcom,vmid", &vmid);
238 if (ret < 0 && ret != -EINVAL) {
239 dev_err(&pdev->dev, "failed to parse qcom,vmid\n");
242 if (!qcom_scm_is_available()) {
247 perms[0].vmid = QCOM_SCM_VMID_HLOS;
248 perms[0].perm = QCOM_SCM_PERM_RW;
249 perms[1].vmid = vmid;
250 perms[1].perm = QCOM_SCM_PERM_RW;
252 rmtfs_mem->perms = BIT(QCOM_SCM_VMID_HLOS);
253 ret = qcom_scm_assign_mem(rmtfs_mem->addr, rmtfs_mem->size,
254 &rmtfs_mem->perms, perms, 2);
256 dev_err(&pdev->dev, "assign memory failed\n");
261 dev_set_drvdata(&pdev->dev, rmtfs_mem);
266 cdev_device_del(&rmtfs_mem->cdev, &rmtfs_mem->dev);
268 put_device(&rmtfs_mem->dev);
273 static int qcom_rmtfs_mem_remove(struct platform_device *pdev)
275 struct qcom_rmtfs_mem *rmtfs_mem = dev_get_drvdata(&pdev->dev);
276 struct qcom_scm_vmperm perm;
278 if (rmtfs_mem->perms) {
279 perm.vmid = QCOM_SCM_VMID_HLOS;
280 perm.perm = QCOM_SCM_PERM_RW;
282 qcom_scm_assign_mem(rmtfs_mem->addr, rmtfs_mem->size,
283 &rmtfs_mem->perms, &perm, 1);
286 cdev_device_del(&rmtfs_mem->cdev, &rmtfs_mem->dev);
287 put_device(&rmtfs_mem->dev);
292 static const struct of_device_id qcom_rmtfs_mem_of_match[] = {
293 { .compatible = "qcom,rmtfs-mem" },
296 MODULE_DEVICE_TABLE(of, qcom_rmtfs_mem_of_match);
298 static struct platform_driver qcom_rmtfs_mem_driver = {
299 .probe = qcom_rmtfs_mem_probe,
300 .remove = qcom_rmtfs_mem_remove,
302 .name = "qcom_rmtfs_mem",
303 .of_match_table = qcom_rmtfs_mem_of_match,
307 static int __init qcom_rmtfs_mem_init(void)
311 ret = class_register(&rmtfs_class);
315 ret = alloc_chrdev_region(&qcom_rmtfs_mem_major, 0,
316 QCOM_RMTFS_MEM_DEV_MAX, "qcom_rmtfs_mem");
318 pr_err("qcom_rmtfs_mem: failed to allocate char dev region\n");
319 goto unregister_class;
322 ret = platform_driver_register(&qcom_rmtfs_mem_driver);
324 pr_err("qcom_rmtfs_mem: failed to register rmtfs_mem driver\n");
325 goto unregister_chrdev;
331 unregister_chrdev_region(qcom_rmtfs_mem_major, QCOM_RMTFS_MEM_DEV_MAX);
333 class_unregister(&rmtfs_class);
336 module_init(qcom_rmtfs_mem_init);
338 static void __exit qcom_rmtfs_mem_exit(void)
340 platform_driver_unregister(&qcom_rmtfs_mem_driver);
341 unregister_chrdev_region(qcom_rmtfs_mem_major, QCOM_RMTFS_MEM_DEV_MAX);
342 class_unregister(&rmtfs_class);
344 module_exit(qcom_rmtfs_mem_exit);
346 MODULE_AUTHOR("Linaro Ltd");
347 MODULE_DESCRIPTION("Qualcomm Remote Filesystem memory driver");
348 MODULE_LICENSE("GPL v2");